Methacrylate polymers have many desirable properties such as crystal clarity, chemical resistance, ease of fabrication and handling, and weatherability which have resulted in their widespread use in sheets and molded articles.
The strength and toughness characteristics of methacrylate polymers are insufficient for some applications but improvements have been achieved by blending methacrylates with other polymers. For example, as disclosed in Modern Plastics Encyclopedia, 1985-1986 polyvinyl chloride has been blended with methacrylates to obtain alloy sheets having high rigidity, dimensional stability and impact-resistance which are thermoformable and easily fabricable. Such alloys, however, are not recommended for exterior use requiring color stability because they tend to yellow.
The toughness characteristics of methacrylates have also been improved by blending with small amounts of polyvinylidene fluoride homopolymer or copolymers thereof containing up to 5 weight percent of another monomer such as disclosed in U.S. Pat. Nos. 3,253,060 and 3,459,834 which are incorporated herein by reference. Blends of methacrylates and small amounts of polyvinylidene fluoride polymer are compatible and exhibit essentially a single transition temperature which is somewhat lower than the transition temperature of the methacrylate component.
Solvent solutions of blends of methacrylates and copolymers of vinylidene fluoride and hexafluoropropylene and films thereof containing glass microspheres are disclosed in U.S. Pat. No. 4,348,312.
In accordance with this invention partially compatible systems suitable for molded articles and the like are obtained with blends of methacrylate polymers and copolymers of vinylidene fluoride and hexafluoropropylene.